Automated verification testing for a motor capacitor

Abstract

A motor capacitor verification unit includes a capacitor selection section coupled to an electric motor employing a motor capacitor for its operation that connects the motor capacitor for verification testing. Also included is a capacitor testing section coupled to the capacitor selection section that evaluates the motor capacitor for operation with the electric motor. Further included is an AC power control section coupled to the capacitor testing section and that only permits application of an AC operating voltage to the electric motor and the motor capacitor after a successful motor capacitor verification as required for electric motor operation. An electric motor operating system, an HVAC operating system and methods of operating an electric motor, retrofitting a motor capacitor verification unit to an electric motor and manufacturing a motor capacitor verification unit for use with an electric motor are also provided.

What is claimed is: 
     
       1. A motor capacitor verification system comprising:
 a capacitor selection electrical circuit coupled to an electric motor, said electric motor employing a motor capacitor for its operation, said capacitor selection electrical circuit configured to connect said motor capacitor for verification testing; 
 a capacitor testing electrical circuit coupled to said capacitor selection electrical circuit and configured to evaluate said motor capacitor for operation with said electric motor; and 
 an AC power control electrical circuit coupled to said capacitor testing electrical circuit, said AC power control electrical circuit configured to only permit application of an AC operating voltage to said electric motor and said motor capacitor after a successful motor capacitor verification as required for operation of said electric motor. 
 
     
     
       2. The motor capacitor verification system of  claim 1  wherein said motor capacitor is selected from the group consisting of:
 a motor run capacitor; 
 a motor start capacitor; 
 a replacement motor run capacitor; and 
 a replacement motor start capacitor. 
 
     
     
       3. The motor capacitor verification system of  claim 1  wherein said capacitor selection section electrical circuit initially connects said motor capacitor to discharge an existing charge on said motor capacitor prior to said verification testing. 
     
     
       4. The motor capacitor verification system of  claim 1  wherein said capacitor selection electrical circuit connects said motor capacitor for said verification testing following discharge of said motor capacitor. 
     
     
       5. The motor capacitor verification system of  claim 1  wherein said capacitor section electrical circuit connects said motor capacitor for operation with said electric motor prior to application of said AC operating voltage. 
     
     
       6. The motor capacitor verification system of  claim 1  wherein said capacitor testing electrical circuit employs said motor capacitor in a test electrical circuit using a reference test signal to provide a motor capacitor output signal having a phase shift that is proportional to a capacitance of said motor capacitor. 
     
     
       7. The motor capacitor verification system of  claim 6  wherein said reference test signal is derived from a motor activation control signal requesting activation of said electric motor. 
     
     
       8. The motor capacitor verification system of  claim 6  wherein said phase shift is determined from base line crossings of said reference test signal and said motor capacitor output signal. 
     
     
       9. The motor capacitor verification system of  claim 1  wherein said AC power control electrical circuit provides an AC voltage control signal to activate connection of said AC operating voltage to said electric motor and said motor capacitor. 
     
     
       10. The motor capacitor verification system of  claim 9  wherein said AC voltage control signal activates an AC operating voltage controller to provide said AC operating voltage to said electric motor and motor capacitor. 
     
     
       11. The motor capacitor verification system of  claim 1  wherein said electric motor is an induction motor. 
     
     
       12. A motor capacitor verification method comprising:
 providing an electric motor employing a motor capacitor required for operation of said electric motor; 
 connecting said motor capacitor for verification testing to an capacitor testing electric circuit configured to determine the state of said motor capacitor; 
 evaluating said motor capacitor for operation with said electric motor using said capacitor testing electric circuit configured to determine the state of said motor capacitor; and 
 with an electric circuit, applying an AC operating voltage to said electric motor and said motor capacitor only after a successful motor capacitor verification using said capacitor testing electric circuit configured to determine the state of said motor capacitor as required for operation of said electric motor. 
 
     
     
       13. The motor capacitor verification method of  claim 12  wherein said motor capacitor is selected from the group consisting of:
 a motor run capacitor; 
 a motor start capacitor; 
 a replacement motor run capacitor; and 
 a replacement motor start capacitor. 
 
     
     
       14. The motor capacitor verification method of  claim 12  wherein said verification testing of said motor capacitor includes analysis of a phase shift provided by said motor capacitor with respect to a reference test signal. 
     
     
       15. The motor capacitor verification method of  claim 14  wherein said phase shift provided by said motor capacitor is proportional to its capacitance value. 
     
     
       16. The motor capacitor verification method of  claim 14  wherein said phase shift is determined by a time difference in baseline signal crossings provided by said motor capacitor and said reference test signal. 
     
     
       17. The motor capacitor verification method of  claim 14  wherein said reference test signal employs a frequency identical to that of said AC operating voltage applied to said electric motor. 
     
     
       18. The motor capacitor verification method of  claim 14  wherein said applied reference test signal is derived from a motor activation control signal. 
     
     
       19. The method as recited in claim motor capacitor verification method of  claim 18  wherein said motor activation control signal is initiated proximate to said motor capacitor or at a central control site. 
     
     
       20. The motor capacitor verification method of  claim 12  wherein said verification testing of said motor capacitor includes preselecting a reference capacitance value for said motor capacitor to provide a comparison for a motor capacitor test result. 
     
     
       21. The motor capacitor verification method of  claim 20  wherein said reference capacitance value is provided from a set of predetermined capacitance values. 
     
     
       22. The motor capacitor verification method of  claim 21  wherein preselecting said reference capacitance value is software directed selected or hardware switch selected. 
     
     
       23. The motor capacitor verification method of  claim 12  wherein said verification testing of said motor capacitor includes preselecting a capacitance tolerance percentage for a test results comparison of said motor capacitor. 
     
     
       24. The motor capacitor verification method of  claim 23  wherein said capacitance tolerance percentage is a fixed percentage or a selectable percentage. 
     
     
       25. The motor capacitor verification method of  claim 12  wherein said electric motor is an induction motor. 
     
     
       26. A motor capacitor verification retrofit method comprising:
 providing an electric motor having a motor capacitor lead connected to said electric motor and having an AC operating voltage controller with a voltage control input connected to a motor activation control signal that activates said AC operating voltage controller for operation of said electric motor; 
 disconnecting said motor capacitor lead from said electric motor and said motor activation control signal from said voltage control input of said AC operating voltage source; 
 connecting said motor capacitor lead to a motor capacitor input provided by a motor capacitor verification unit; 
 connecting said electric motor to a motor capacitor output provided by said motor capacitor verification unit; 
 connecting said motor activation control signal to an activation input of said motor capacitor verification unit; and 
 connecting an AC voltage control output of said motor capacitor verification unit to said voltage control input of said AC operating voltage controller. 
 
     
     
       27. The motor capacitor verification retrofit method of  claim 26  wherein said motor capacitor input provides connecting and routing of said motor capacitor during verification testing of said motor capacitor. 
     
     
       28. The motor capacitor verification retrofit method of  claim 26  wherein said motor capacitor output provides connecting of said motor capacitor to said electric motor for normal motor operation. 
     
     
       29. The motor capacitor verification retrofit method of  claim 26  wherein said AC voltage control output of said motor capacitor verification unit controls activation of said AC operating voltage controller. 
     
     
       30. The motor capacitor verification retrofit method of  claim 26  wherein said motor activation control signal controls activation of verification testing of said motor capacitor. 
     
     
       31. An electric motor system comprising:
 one or more electric motors, each employing one or more motor capacitors required for electric motor operation; and 
 a motor capacitor verification unit, including: a capacitor selection electrical circuit, coupled to each of said one or more electric motors and said one or more motor capacitors, that connects each of said one or more motor capacitors for verification testing, a capacitor testing electrical circuit, coupled to said capacitor verification electrical circuit, that evaluates said one or more motor capacitors required for electric motor operation, and an AC power control electrical circuit, coupled to said capacitor testing electrical circuit, that only permits application of an AC operating voltage to said one or more electric motors and said one or more motor capacitors following a successful motor capacitor verification of said one or more motor capacitors required for electric motor operation. 
 
     
     
       32. The electric motor system of  claim 31  wherein each of said one or more motor capacitors is selected from the group consisting of:
 a motor run capacitor; 
 a motor start capacitor; 
 a replacement motor run capacitor; and 
 a replacement motor start capacitor. 
 
     
     
       33. The electric motor system of  claim 31  wherein said capacitor selection electrical circuit initially connects said one or more motor capacitors to discharge an existing charge on each of said one or more motor capacitors prior to verification testing. 
     
     
       34. The electric motor system of  claim 31  wherein said capacitor selection electrical circuit connects said one or more motor capacitors for verification testing following discharge of said motor capacitor. 
     
     
       35. The electric motor system of  claim 31  wherein said capacitor testing electrical circuit employs each of said one or more motor capacitors in a test electrical circuit using a reference test signal to provide a motor capacitor output signal having a phase shift that is proportional to a capacitance value of said motor capacitor. 
     
     
       36. The electric motor system of  claim 35  wherein said input reference signal is derived from a motor activation control signal requesting activation of said electric motor. 
     
     
       37. The electric motor system of  claim 35  wherein said phase shift is determined from base line crossings of said reference test signal and said motor capacitor output signal. 
     
     
       38. The electric motor system of  claim 31  wherein said AC power control electrical circuit provides an AC voltage control signal to activate connection of said AC operating voltage to said one or more electric motors and said one or more motor capacitors. 
     
     
       39. The electric motor system of  claim 38  wherein said AC voltage control signal activates an AC operating voltage controller. 
     
     
       40. The electric motor system of  claim 31  wherein said motor capacitor verification unit is implemented as a divided motor capacitor verification unit having a first motor capacitor verification subunit and a second motor capacitor verification subunit that operate separately of one another. 
     
     
       41. The electric motor system of  claim 31  wherein said motor capacitor verification unit is implemented as a distributed motor capacitor verification unit having separate capacitor selection and AC power control electrical circuits that share a capacitor testing section electrical circuit. 
     
     
       42. The electric motor system of  claim 31  wherein each of said one or more electric motors is an induction motor. 
     
     
       43. A heating ventilation air conditioning (HVAC) system comprising:
 a compressor unit having compressor and fan motors that respectively employ a compressor motor capacitor and a fan motor capacitor for their operation; 
 a blower motor unit having a blower motor that employs a blower motor capacitor for its operation; and 
 a motor capacitor verification unit, including: a capacitor selection electrical circuit that connects said compressor, fan and blower motor capacitors for verification testing; 
 a capacitor testing electrical circuit, coupled to said capacitor selection electrical circuit, that evaluates said compressor, fan and blower motor capacitors for operation with their respective compressor, fan and blower motors, and an AC power control electrical circuit, coupled to said capacitor testing section electrical circuit, that only permits application of an AC operating voltage to said compressor, fan and blower motors and their respective compressor, fan and blower motor capacitors following successful compressor, fan and blower motor capacitor verifications required for compressor, fan and blower motor operations. 
 
     
     
       44. The heating ventilation air conditioning (HVAC) system of  claim 43  wherein said compressor, fan, and blower motor capacitors are motor run capacitors. 
     
     
       45. The heating ventilation air conditioning (HVAC) system of  claim 43  wherein at least one of said compressor and said blower motor units further includes a replacement motor capacitor that is connected for substitution with an existing motor capacitor having a failed motor capacitor verification. 
     
     
       46. The heating ventilation air conditioning (HVAC) system of  claim 43  wherein said motor capacitor verification unit is implemented as a divided motor capacitor verification unit having a compressor unit motor capacitor verification subunit and a blower unit motor capacitor verification subunit that operate separately of one another. 
     
     
       47. The heating ventilation air conditioning (HVAC) system of  claim 43  wherein said motor capacitor verification unit is implemented as a distributed motor capacitor verification unit having separate capacitor selection and AC power control electrical circuits for said compressor unit and said blower unit that share said capacitor testing electrical circuit. 
     
     
       48. The heating ventilation air conditioning (HVAC) system of  claim 43  wherein a failed motor capacitor verification is indicated proximate said condenser and said blower units or remotely from said condenser and said blower units and in a visual or auditory manner. 
     
     
       49. The heating ventilation air conditioning (HVAC) system of  claim 48  wherein said failed motor capacitor verification is indicated on a central HVAC control unit.